Display device and manufacturing method thereof

ABSTRACT

A method for manufacturing a display device includes forming a first gate metal wire on a substrate, forming a first insulation layer that covers the first gate metal wire, forming a second gate metal wire on the first insulation layer, forming a second main insulation layer that covers the second gate metal wire, forming a second auxiliary insulation layer on the second main insulation layer, forming an exposed portion of an upper surface of the second main insulation layer by polishing the second auxiliary insulation layer, and forming a first data metal wire on the second main insulation layer and the second auxiliary insulation layer.

CROSS-REFERENCE TO RELATED APPLICATION

Korean Patent Application No. 10-2016-0135041 filed on Oct. 18, 2016, inthe Korean Intellectual Property Office, and entitled: “Display Deviceand Manufacturing Method Thereof,” is incorporated by reference hereinin its entirety.

BACKGROUND 1. Field

Embodiments relate to a display device and a manufacturing methodthereof.

2. Description of the Related Art

Display devices include a liquid crystal display (LCD), a plasma displaypanel (PDP), an organic light emitting diode (OLED) display, a fieldemission display (FED), and an electrophoretic display device.Generally, in the display device, the plurality of transistors and oneor more capacitors are included in one pixel.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the invention andtherefore it may contain information that does not form the prior artthat is already known in this country to a person of ordinary skill inthe art.

SUMMARY

Embodiments are directed to a method for manufacturing a display device,the method including forming a first gate metal wire on a substrate,forming a first insulation layer that covers the first gate metal wire,forming a second gate metal wire on the first insulation layer, forminga second main insulation layer that covers the second gate metal wire,forming a second auxiliary insulation layer on the second maininsulation layer, forming an exposed portion of an upper surface of thesecond main insulation layer by polishing the second auxiliaryinsulation layer, and forming a first data metal wire on the second maininsulation layer and the second auxiliary insulation layer. An uppersurface of the second auxiliary insulation layer may be formed on thesame horizontal plane as the exposed portion of the upper surface of thesecond main insulation layer, and the uppermost layer of the second maininsulation layer may include a silicon nitride, and the second auxiliaryinsulation layer may include a silicon oxide.

Forming the exposed portion of the upper surface of the second maininsulation layer by polishing the second auxiliary insulation layer mayinclude coating a first slurry on a surface of the second auxiliaryinsulation layer, and the first slurry may include first abrasives thatpolish the second auxiliary insulation layer and may include a firstpolishing inhibitor that inhibits the polishing of the second maininsulation layer.

A thickness of the second auxiliary insulation layer may be greater thana step of the upper surface of the second main insulation layer, thestep of the upper surface of the second main insulation layer being agap between a first portion of the upper surface of the second maininsulation layer having a highest height and a second portion of theupper surface of the second main insulation layer having a lowestheight.

The method may further include forming a third main insulation layerthat covers the first data metal wire, forming a third auxiliaryinsulation layer on the third main insulation layer, forming an exposedportion of an upper surface of the third main insulation layer bypolishing the third auxiliary insulation layer, and forming a seconddata metal wire on the third main insulation layer and the thirdauxiliary insulation layer. An upper surface of the third auxiliaryinsulation layer may be disposed on the same horizontal plane as theexposed portion of the upper surface of the third main insulation layer.

The polishing of the third auxiliary insulation layer may includecoating a second slurry on a surface of the third auxiliary insulationlayer, and the second slurry may include second abrasives that polishthe third auxiliary insulation layer and may include a second polishinginhibitor that inhibits the polishing of the third main insulationlayer.

The third main insulation layer may include a silicon nitride.

A thickness of the third auxiliary insulation layer may be greater thana step of the upper surface of the third main insulation layer, the stepof the upper surface of the third main insulation layer being a gapbetween a third portion of the upper surface of the third maininsulation layer having a highest height, and a fourth portion of thethird main insulation layer having a lowest height.

Forming the exposed portion of the upper surface of the second maininsulation layer may include polishing using a polishing device thatincludes a polishing portion that polishes a target object while beingrotated, and a polishing control portion that controls a rotation speedof the polishing portion by measuring a change in a frictional force ofthe polishing portion, and forming the exposed portion of the uppersurface of the second main insulation layer by polishing the secondauxiliary insulation layer may include measuring the change in thefrictional force of the polishing portion by sensing the rotation speedof the polishing portion by the polishing control portion, and stoppingrotation of the polishing portion at the time that the frictional forceis changed by the polishing control portion.

Embodiments are also directed to a display device, including asubstrate, a first gate metal wire that is disposed on the substrate, afirst insulation layer that covers the first gate metal wire, a secondgate metal wire that is disposed on the first insulation layer, a secondmain insulation layer that covers the second gate metal wire, a secondauxiliary insulation layer that is disposed on the second maininsulation layer, and a first data metal wire that is disposed on thesecond main insulation layer and the second auxiliary insulation layer.An upper surface of the second auxiliary insulation layer may bedisposed on the same horizontal plane as a part of an upper surface ofthe second main insulation layer, the uppermost layer of the second maininsulation layer may include a silicon nitride, and the second auxiliaryinsulation layer may include a silicon oxide.

The display device may further include a third main insulation layerthat covers the first data metal wire, a third auxiliary insulationlayer that is disposed on the third main insulation layer, and a seconddata metal wire that is disposed on the third main insulation layer andthe third auxiliary insulation layer. An upper surface of the thirdauxiliary insulation layer may be disposed on the same horizontal planeas a part of an upper surface of the third main insulation layer, andthe third main insulation layer may include a silicon nitride.

A part of the upper surface of the third main insulation layer that isdisposed between the first data metal wire and the second data metalwire may directly contact the second metal wire.

A thickness of the third main insulation layer may be smaller than athickness of the second main insulation layer.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of skill in the art by describingin detail example embodiments with reference to the attached drawings inwhich:

FIG. 1 illustrates a cross-sectional view of a method for manufacturinga display device according to an example embodiment.

FIG. 2 illustrates a schematic perspective view of a polishing deviceused in the method for manufacturing the display device according to anexample embodiment.

FIG. 3 illustrates the next stage after that of FIG. 1.

FIG. 4 illustrates the next stage after that of FIG. 3.

FIG. 5 illustrates the next stage after that of FIG. 4.

FIG. 6 illustrates the next stage after that of FIG. 5.

FIG. 7 illustrates an equivalent circuit diagram of a pixel of a displaydevice according to an example embodiment.

FIG. 8 illustrates a cross-sectional view of the display deviceaccording to an example embodiment.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey example implementations to those skilled in the art. In thedrawing figures, the dimensions of layers and regions may be exaggeratedfor clarity of illustration. Like reference numerals refer to likeelements throughout.

In the specification, unless explicitly described to the contrary, theword “comprise” and variations such as “comprises” or “comprising” willbe understood to imply the further inclusion of other elements. Inaddition, in the specification, it will be understood that when anelement such as a layer, a film, a region, or a substrate is referred toas being “over” or “on” another element, it can be “directly on” theother element or intervening elements may also be present. Further, theword “over” or “on” means positioning on or below the object portion,but does not essentially mean positioning on the upper side of theobject portion based on a gravity direction.

In this specification, the phrase “on a plane” means viewing a targetportion from the top, and the phrase “on a cross-section” means viewinga cross-section formed by vertically cutting a target portion from theside.

A display device may include the plurality of transistors and one ormore capacitors in one pixel, and a separate wire may be further formedor an existing wire may be omitted, so that the display device may alsobe formed to have various structures. Here, the pixel refers to aminimum unit displaying an image, and the display device displays animage through the plurality of pixels.

Hereinafter, a manufacturing method of a display device according to anexample embodiment will be described with reference to FIG. 1 to FIG. 6.

FIG. 1 is a cross-sectional view that shows one stage of a manufacturingmethod of a display device according to an example embodiment, FIG. 2 isa schematic perspective view of a polishing device used in themanufacturing method of the display device according to an exampleembodiment, and FIG. 3 shows the next stage after that of FIG. 1. FIG. 4shows the next stage after that of FIG. 3, FIG. 5 shows the next stageafter that of FIG. 4, and FIG. 6 shows the next stage after that of FIG.5.

As shown in FIG. 1, an active layer 130 is provided on a substrate 110,and a gate insulation layer 140 that covers the active layer 130 isprovided on the active layer 130. The active layer 130 may be formed by,for example, forming an amorphous silicon layer and then crystallizingthe amorphous silicon layer using a laser crystallization process. Theamorphous silicon layer may be formed using, for example, a low pressurechemical vapor deposition method, a normal pressure chemical vapordeposition method, a plasma enhanced chemical vapor deposition method, asputtering method, a vacuum evaporation method, and the like. The gateinsulation layer 140 may include, for example, a silicon oxide (SiO_(x))or a silicon nitride (SiN_(x)).

A first gate metal wire 151 may be formed on the gate insulation layer140. The first gate metal wire 151 may include, for example, one or moreof molybdenum (Mo), a molybdenum alloy, copper (Cu), a copper alloy,aluminum (Al), an aluminum alloy, etc.

A first insulation layer 161 may cover the first gate metal wire 151.The first insulation layer 161 may include, for example, a silicon oxide(SiO_(x)) or a silicon nitride (SiN_(x)).

A second gate metal wire 152 may be on the first insulation layer 161.The second gate metal wire 152 may include, for example, one or more ofmolybdenum (Mo), a molybdenum alloy, copper (Cu), a copper alloy,aluminum (Al), or an aluminum alloy, etc.

A second main insulation layer 1621 may cover the second gate metal wire152. The second main insulation layer 1621 may be provided as a doublelayer of a lower layer and an upper layer. In this case, the lower layermay include, for example, a silicon oxide, and the upper layer mayinclude, for example, a silicon nitride. In an implementation, thesecond main insulation layer 1621 may be provided as a plurality ofvarious layers in which the uppermost layer of the second maininsulation layer 1621 includes a silicon nitride.

A second auxiliary insulation layer 1622 may be on the second maininsulation layer 1621. The second auxiliary insulation layer 1622 mayinclude, for example, a silicon oxide.

In an implementation, a thickness t 1 of the deposited second auxiliaryinsulation layer 1622 may be greater than a step d1 of an upper surfaceof the second main insulation layer 1621. Here, the step d1 of the uppersurface of the second main insulation layer 1621 may be a distancebetween a first portion P having the maximum height and a second portionP2 having the minimum height in the upper surface. Here, a height of thefirst portion P1 or a height of the second portion P2 is defined as ashortest distance from an upper surface of the substrate 110 to an uppersurface of the first portion or an upper surface of the second portionP2.

As shown in FIG. 1, a polishing process may be performed, for example,by using a polishing device that performs a chemical mechanicalpolishing process.

Referring to FIG. 2, a detailed structure of an example of the polishingdevice will be described in detail.

As shown in FIG. 2, a polishing part CMP may include, for example, apolishing portion 50 that polishes a target object P by being rotated,and a polish control portion 60 that controls a rotation speed of thepolishing portion 50 by measuring a change in a frictional force. Thepolishing portion 50 may includes a first polishing portion 20 and asecond polishing portion 30 that face each other. The target object Pmay be placed on the second polishing portion 30. The first polishingportion 20 and the second polishing portion 30 may rotate to polish thetarget object P that is placed therebetween. A first slurry 51 may besupplied to the surface of the target object P by using a nozzle 40. Thefirst slurry 51 may be a material for easily polishing the target objectP.

The target object P shown in FIG. 2 corresponds to a display device 100shown in FIG. 1 and FIG. 3 to FIG. 5. FIG. 1 and FIG. 3 to FIG. 5 onlyillustrate the first polishing portion 20 for better understanding andease of description.

In the present example embodiment, the display device 100 is attached onthe second polishing portion 30 and the polishing process is performed,but this is not restrictive. The display device 100 may be disposedbelow the first polishing portion 20 and the polishing process may beperformed according to another example embodiment.

As shown in FIG. 1, the first slurry 51 is coated on the surface of thesecond auxiliary insulation layer 1622. The first slurry 51 may include,for example, first abrasives that polish the second auxiliary insulationlayer 1622, a first polishing inhibitor that inhibits the polishing ofthe second main insulation layer 1621, a dispersant that disperses thefirst abrasives, a dispersion stabilizer that helps maintain dispersionof the first abrasives, and a pH regulator. The first abrasives mayinclude, for example, silica (SiO₂), ceria (CeO₂), alumina (Al₂O₃),zirconia (ZrO₂), tin oxide (SnO₂), manganese oxide (MnO₂), and the like.The first polishing inhibitor may include, for example, polyacrylicacid.

The second auxiliary insulation layer 1622 where the first slurry 51 iscoated may be polished by rotating the first polishing portion 20 of thepolishing device CMP. The first abrasives included in the first slurry51 helps the first polishing portion 20 to more easily polish the secondauxiliary insulation layer 1622.

Next, as shown in FIG. 3, the second auxiliary insulation layer 1622 maybe continuously polished using the polishing device CMP to partiallyexpose an upper surface 1621 a of the second main insulation layer 1621.The operation of the polishing device CMP may be stopped when the uppersurface 1621 a of the second main insulation layer 1621 is partiallyexposed. The first polishing inhibitor included in the first slurry 51inhibits the polishing of the second main insulation layer 1621 exposedto the first polishing inhibitor, and, when sensing a change infrictional force, the polishing control portion 60 stops the rotation ofthe polishing portion 50. In this case, an upper surface 1622 a of thesecond auxiliary insulation layer 1622 is disposed on the samehorizontal plane as the exposed upper surface 1621 a of the second maininsulation layer 1621. Through such a polishing process, a secondinsulation layer 162 of which the upper surface is planarized is formed.The second insulation layer 162 includes the second main insulationlayer 1621 and the second auxiliary insulation layer 1622.

Next, as shown in FIG. 4, a first data metal wire 171 is formed on thesecond insulation layer 162 that includes the second main insulationlayer 1621 and the second auxiliary insulation layer 1622, a third maininsulation layer 1631 and a third auxiliary insulation layer 1632 areformed on the first data metal wire 171, a second slurry 52 is coated onthe third auxiliary insulation layer 1632, and then the third auxiliaryinsulation layer 1632 where the second slurry 52 is coated is polishedby rotating the first polishing portion 20 of the polishing device CMP.This is described in further detail below.

The data metal wire 171 may be formed in multiple layers, for example,in which metal layers including any one of aluminum (Al), an aluminumalloy, molybdenum (Mo), a molybdenum alloy, copper (Cu), and a copperalloy are laminated, and for example, may be formed of triple layers oftitanium/aluminum/titanium (Ti/Al/Ti), triple layers ofmolybdenum/aluminum/molybdenum (Mo/Al/Mo), or triple layers ofmolybdenum/copper/molybdenum (Mo/Cu/Mo). The second insulation layer 162may be planarized before the first data metal wire 171 is formed, andaccordingly, the first data metal wire 171 disposed on the secondinsulation layer 162 may be formed without a step. Accordingly, thefirst data metal wire 171 may be easily patterned, for example, usinglithography.

After the first data metal wire 171 is formed, the third main insulationlayer 1631 that covers the first data metal wire 171 may be formed. Thethird main insulation layer 1631 may include, for example, a siliconnitride.

Then, the third auxiliary insulation layer 1632 may be formed on thethird main insulation layer 1631. The third auxiliary insulation layer1632 may include, for example, a silicon oxide. In this case, athickness t2 of the deposited third auxiliary insulation layer 1632 maybe greater than a step d2 of an upper surface of the third maininsulation layer 1631. Here, the step d2 of the upper surface of thethird main insulation layer 1631 may be a gap between a third portion P3that has the highest height in the upper surface of the third maininsulation layer 1631 and a fourth portion P4 that has the lowest heightin the upper surface of the third main insulation layer 1631. Here, theheight of the third portion P3 or the height of the fourth portion P4are defined as the shortest distance to an upper surface of the thirdportion P3 or an upper surface of the fourth portion P from the uppersurface of the substrate 110.

Second slurry 52 may be coated on a surface of the third auxiliaryinsulation layer 1632. The second slurry 52 may include, for example,second abrasives that polish the third auxiliary insulation layer 1632,a second abrasives inhibitor that inhibits the polishing of the thirdmain insulation layer 1631, a dispersant that disperses secondabrasives, a dispersion stabilizer that helps maintain dispersion of thesecond abrasives, and a pH regulator. The second abrasives may include,for example, silica (SiO₂), ceria (CeO₂), alumina (Al₂O₃), zirconia(ZrO₂), tin oxide (SnO₂), manganese oxide (MnO₂), and the like. Thesecond polishing inhibitor may include, for example, polyacrylic acid.

The third auxiliary insulation layer 1632 where the second slurry 52 iscoated may be polished, for example, by rotating the first polishingportion 20 of the polishing device CMP. The second abrasives included inthe second slurry 52 help the first polishing portion 20 to more easilypolish the third auxiliary insulation layer 1632.

Next, as shown in FIG. 5, the third auxiliary insulation layer 1632 maybe continuously polished by using the polishing device CMP to partiallyexpose an upper surface 1631 a of the third main insulation layer 1631.The operation of the polishing device CMP may be stopped when the uppersurface 1631 a of the third main insulation layer 1631 is partiallyexposed. The second polishing inhibitor included in the second slurry 53inhibits the polishing of the third main insulation layer 1631 exposedto the second polishing inhibitor, and, when sensing a change infrictional force, the polishing control portion 60 may stop the rotationof the polishing portion 50. In this case, an upper surface 1632 a ofthe third auxiliary insulation layer 1632 is disposed on the samehorizontal plane as the exposed upper surface 1631 a of the third maininsulation layer 1631. Through such a polishing process, a thirdinsulation layer 163 of which the upper surface is planarized is formed.The third insulation layer 163 includes the third main insulation layer1631 and the third auxiliary insulation layer 1632.

Next, as shown in FIG. 6, a second data metal wire 172 may be formed onthe third insulation layer 163 that includes the third main insulationlayer 1631 and the third auxiliary insulation layer 1632. The seconddata metal wire 172 may be formed, for example, in multiple layers, inwhich metal layers including any one, for example, of aluminum (Al), analuminum alloy, molybdenum (Mo), a molybdenum alloy, copper (Cu), and acopper alloy are laminated, and for example, may be formed of triplelayers of titanium/aluminum/titanium (Ti/Al/Ti), triple layers ofmolybdenum/aluminum/molybdenum (Mo/Al/Mo), or triple layers ofmolybdenum/copper/molybdenum (Mo/Cu/Mo).

The second data metal wire 172 may be partially overlapped with thefirst data metal wire 171. In this case, the third insulation layer 163may be planarized, and the second data metal wire 172 that is disposedon the third insulation layer 163 may be formed without a step.Accordingly, the second data metal wire 172 may be easily patterned, forexample, using lithography.

The third insulation layer 163 that is disposed between the first datametal wire 171 and the second data metal wire 172 may be planarized, andthus the thickness of the third insulation layer 163 can be made thin.Accordingly, capacitance of a capacitor that includes the first datametal wire 171, the second data metal wire 172, and the third maininsulation layer 1631 that is disposed between the first data metal wire171 and the second data metal wire 172 may be maximized.

In addition, the second insulation layer 162 and the third insulationlayer 163 may be planarized, and both of the first data metal wire 171and the second data metal wire 172 may be formed without steps such thata short circuit between the first data metal wire 171 and the seconddata metal wire 172 may be minimized. Accordingly, a display devicehaving high resolution may be readily manufactured.

Hereinafter, a display device manufactured by using the manufacturingmethod of the display device according to the above-described exampleembodiment will be described in detail with reference to FIG. 7 and FIG.8.

FIG. 7 is an equivalent circuit diagram of a pixel of a displayaccording to an example embodiment.

In an example embodiment, as shown in FIG. 7, one pixel of displaydevice may include a driving transistor T1, a switching transistor T2, acompensation transistor T3, a storage capacitor Cst, a parasiticcapacitor Cpa, and an organic light emitting diode (OLED). In addition,a scan line 121 that transmits a scan signal Sn, a data line 71 thattransmits a data signal Dm, and a driving voltage line 174 thattransmits a driving voltage ELVDD may be connected to one pixel.

The first gate metal wire 151 or the second gate metal wire 152 mayinclude the scan line 121, and the first data metal wire 171 or thesecond data metal wire 172 may include the data line 71 and the drivingvoltage line 174.

The driving transistor T1 includes a control terminal, an inputterminal, and an output terminal, and the control terminal may beconnected to the switching transistor T2, the input terminal may beconnected to the driving voltage line 174, and the output terminal maybe connected to the organic light emitting diode OLED. The drivingtransistor T1 may allow an output current Id, of which a magnitude maybe changed according to a voltage applied between the control terminaland the output terminal, to flow.

The switching transistor T2 includes a control terminal, an inputterminal, and an output terminal, and the control terminal may beconnected to the scan line 121, the input terminal may be connected tothe data line 71, and the output terminal may be connected to thedriving transistor T1. The switching transistor T2 may transmit a datasignal Dm applied to the data line 71 to the driving transistor T1 inresponse to the scan signal Dn applied to the scan line 121.

The compensation transistor T3 includes a control terminal, an inputterminal, and an output terminal, and the control terminal may beconnected to a compensation control line comp, the input terminal may beconnected to an initialization voltage line 177, and the output terminalmay be connected to the driving transistor T1.

The storage capacitor Cst may be connected between the control terminalof the driving transistor T1 and the initialization voltage line 177.The storage capacitor Cst may charge a data signal applied to thecontrol terminal of the driving transistor T1 and maintain the datasignal even after the switching transistor T2 is turned off.

The organic light emitting diode OLED may include an anode that isconnected to the output terminal of the driving transistor T1 and acathode that is connected to a common voltage ELVSS. The organic lightemitting diode OLED may display emit light while changing the intensitythereof according to the output current Id of the driving transistor T1.

A connection relationship of the transistors T1, T2, and T3, the storagecapacitor Cst, the parasitic capacitor Cpa, and the organic lightemitting diode OLED may be changed.

In the example embodiment, the structure including the three transistorsand the two capacitors is illustrated, but the present disclosure is notlimited thereto, and the numbers of transistors and capacitors may bevariously changed.

Hereinafter, a detailed structure of the pixel of the display deviceillustrated in FIG. 7 will be described with reference to FIG. 8.

FIG. 8 is a cross-sectional view of the display device according to thepresent example embodiment.

In the example embodiment shown in FIG. 8, an active layer 130 isdisposed on a substrate 110 of the display device. The substrate 110 maybe, for example, a flexible insulative substrate made of glass, quartz,ceramic, or plastic. The active layer 130 may include, for example, apolycrystalline silicon layer. A gate insulation layer 140 is disposedon the active layer 130. The first gate metal wire 151 is disposed onthe gate insulation layer 140. A wire which is disposed whileoverlapping the active layer 130, in the first gate metal wire 151, maybe a gate electrode.

A first insulation layer 161 covering the first gate metal wire 151 isdisposed on the first gate metal wire 151. Although it is notillustrated in FIG. 8, a second gate metal wire 152 (refer to FIG. 5)may be disposed on the first insulation layer 161.

A second main insulation layer 1621 that covers the first insulationlayer 161 is disposed on the first insulation layer 161. A secondauxiliary insulation layer 1622 is disposed on the second maininsulation layer 1621. The uppermost layer of the second main insulationlayer 1621 includes a silicon nitride, and the second auxiliaryinsulation layer 1622 includes a silicon oxide.

An upper surface 1622 a of the second auxiliary insulation layer 1622 isdisposed on the same horizontal plane as a part of an upper surface 1621a of the second main insulation layer 1621. The upper surface 1622 a ofthe second auxiliary insulation layer 1622 and the upper surface 1621 aof the second main insulation layer 1621 are planarized with respect toeach other. In addition, the first data metal wire 171 is disposed on asecond insulation layer 162 that includes the second main insulationlayer 1621 and the second auxiliary insulation layer 1622. As described,the second insulation layer 162 is planarized, and accordingly, thefirst data metal wire 171 that is disposed on the second insulationlayer 162 may not have a step. The first data metal wire 171 may includethe data line 71, a source electrode 173, or a drain electrode 175. Thesource electrode 173 and the drain electrode 175 are connected with theactive layer 130.

In addition, a third main insulation layer 1631 that covers the firstdata metal wire 171 is disposed on the first data metal wire 171. Athird auxiliary insulation layer 1632 is disposed on the third maininsulation layer 1631. The third main insulation layer 1631 may include,for example, a silicon nitride and the third auxiliary insulation layer1632 may include, for example, a silicon oxide.

An upper surface 1632 a of the third auxiliary insulation layer 1632 isdisposed on the same horizontal plane as an upper surface 1631 a of thethird main insulation layer 1631. The upper surface 1632 a of the thirdauxiliary insulation layer 1632 and the upper surface 1631 a of thethird main insulation layer 1631 may be planarized with respect to eachother. Further, a second data metal wire 172 is disposed on a thirdinsulation layer 163 that includes the third main insulation layer 1631and the third auxiliary insulation layer 1632. The third insulationlayer 163 may be planarized, and the second data metal wire 172 that isdisposed on the second insulation layer 162 may not have a step.

A part of the upper surface 1631 a of the third main insulation layer1631 that is disposed between the first data metal wire 171 and thesecond data metal wire 172 may directly contact the second data metalwire 172. Thus, capacitance of the parasitic capacitor Cpa that includesthe first data metal wire 171, the second data metal wire 172, and thethird main insulation layer 1631 that is disposed between the first datametal wire 171 and the second data metal wire 172 may be maximized. Inaddition, a thickness t4 of the third main insulation layer 1631 may besmaller than a thickness t3 of the second main insulation layer 1621.Accordingly, capacitance of the parasitic capacitor Cpa may be furthermaximized.

A passivation layer 180 is disposed on the second data metal wire 172.The passivation layer 180 may include, for example, an organic material,such as a polyacryl-based resin and a polyimide-based resin, a laminatedlayer of an organic material and an inorganic material, or the like.

A pixel electrode 710 is disposed on the passivation layer 180. Thepixel electrode 710 may be formed of, for example, a transparentconductive material such as an indium tin oxide (ITO), an indium zincoxide (IZO), a zinc oxide (ZnO), or an indium oxide (In2O3), or areflective metal such as lithium (Li), calcium (Ca),fluorolithium/calcium (LiF/Ca), fluorolithium/aluminum (LiF/Al),aluminum (Al), silver (Ag), magnesium (Mg), or gold (Au). The pixelelectrode 710 is electrically connected with the drain electrode 175.

A pixel defining layer 350 is disposed on the passivation layer 180 andan edge portion of the pixel electrode 710. The pixel defining layer 350has an opening 351 that overlaps the pixel electrode 710. An organicemission layer 720 is disposed in the opening 351 of the pixel defininglayer 350. The organic emission layer 720 may be formed of, for example,multiple layers including one or more of an emission layer, a holeinjection layer HIL, a hole transport layer HTL, an electron transportlayer ETL, and an electron injection layer EIL. The emission layer maybe, for example, an organic material or an inorganic material. In thecase where the organic emission layer 720 includes all of these layers,the hole injection layer may be disposed on the pixel electrode 710 thatis an anode electrode, and the hole transport layer, the emission layer,the electron transport layer, and the electron injection layer may besequentially laminated thereon.

A common electrode 730 is disposed on the pixel defining layer 350 andthe organic emission layer 720. The common electrode 730 may be formedof, for example, a transparent conductive material such as an indium tinoxide (ITO), an indium zinc oxide (IZO), a zinc oxide (ZnO). or anindium oxide (In2O3), or a reflective metal such as lithium (Li),calcium (Ca), fluorolithium/calcium (LiF/Ca), fluorolithium/aluminum(LiF/Al), aluminum (Al), silver (Ag), magnesium (Mg), or gold (Au). Thecommon electrode 730 may be a cathode electrode of the organic lightemitting diode OLED. The pixel electrode 710, the organic emission layer720, and the common electrode 730 may form the organic light emittingdiode OLED.

By way of summation and review, the transistors and the capacitors mayinclude a plurality of lines and an insulation layer. When resolution ofa display device is increased, a size of a pixel may be decreased. In anultra high-resolution display device, many wires may be disposed in anarrow space, so that an area having a large step between the wireswithin a pixel may be generated. In this case, when a photolithographyprocess is performed, a pattern defect of the wire may be generated dueto a pattern defect of a photosensitive film.

In addition, implementation of such an ultra high-resolution displaydevice may call for an increase of capacitance of the capacitor.However, in order to increase the capacitance of the capacitor, athickness of an insulation layer that is disposed between wires may bereduced, which may increase the possibility of a short circuit, and theoccurrence of the short circuit may be increased in an area having alarge step.

As described above, embodiments may provide a display device capable ofimplementing high resolution, and a method of manufacturing the same.According to example embodiments, a short circuit between data metalwires may be minimized, and sufficient capacitance may be assured.Further, a data metal wire may be easily patterned. Accordingly, thehigh resolution display device may be readily manufactured.

DESCRIPTION OF SYMBOLS

51: first slurry, 52: second slurry, 110: substrate, 130: active layer,140: gate insulation layer, 151: first gate metal wire, 152: second gatemetal wire, 161: first insulation layer, 1621: second main insulationlayer, 1622: second main insulation layer, 163: third insulation layer,1631: third main insulation layer, 1632: third auxiliary insulationlayer, 171: first data metal wire, 172: second data metal wire.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope of the present invention asset forth in the following claims.

What is claimed is:
 1. A method for manufacturing a display device, the method comprising: forming a first gate metal wire on a substrate; forming a first insulation layer that covers the first gate metal wire; forming a second gate metal wire on the first insulation layer; forming a second main insulation layer that covers the second gate metal wire; forming a second auxiliary insulation layer on the second main insulation layer; forming an exposed portion of an upper surface of the second main insulation layer by polishing the second auxiliary insulation layer; and forming a first data metal wire on the second main insulation layer and the second auxiliary insulation layer, wherein: an upper surface of the second auxiliary insulation layer is formed on the same horizontal plane as the exposed portion of the upper surface of the second main insulation layer, and the uppermost layer of the second main insulation layer includes a silicon nitride, and the second auxiliary insulation layer includes a silicon oxide.
 2. The method as claimed in claim 1, wherein: forming the exposed portion of the upper surface of the second main insulation layer by polishing the second auxiliary insulation layer includes coating a first slurry on a surface of the second auxiliary insulation layer, and the first slurry includes first abrasives that polish the second auxiliary insulation layer and includes a first polishing inhibitor that inhibits the polishing of the second main insulation layer.
 3. The method as claimed in claim 1, wherein a thickness of the second auxiliary insulation layer is greater than a step of the upper surface of the second main insulation layer, the step of the upper surface of the second main insulation layer being a gap between a first portion of the upper surface of the second main insulation layer having a highest height and a second portion of the upper surface of the second main insulation layer having a lowest height.
 4. The method as claimed in claim 1, further comprising: forming a third main insulation layer that covers the first data metal wire; forming a third auxiliary insulation layer on the third main insulation layer; forming an exposed portion of an upper surface of the third main insulation layer by polishing the third auxiliary insulation layer; and forming a second data metal wire on the third main insulation layer and the third auxiliary insulation layer, wherein: an upper surface of the third auxiliary insulation layer is disposed on the same horizontal plane as the exposed portion of the upper surface of the third main insulation layer.
 5. The method as claimed in claim 4, wherein: the polishing of the third auxiliary insulation layer includes coating a second slurry on a surface of the third auxiliary insulation layer, and the second slurry includes second abrasives that polish the third auxiliary insulation layer and includes a second polishing inhibitor that inhibits the polishing of the third main insulation layer.
 6. The method as claimed in claim 5, wherein the third main insulation layer includes a silicon nitride.
 7. The method as claimed in claim 4, wherein a thickness of the third auxiliary insulation layer is greater than a step of the upper surface of the third main insulation layer, the step of the upper surface of the third main insulation layer being a gap between a third portion of the upper surface of the third main insulation layer having a highest height, and a fourth portion of the third main insulation layer having a lowest height.
 8. The method as claimed in claim 1, wherein forming the exposed portion of the upper surface of the second main insulation layer includes polishing using a polishing device that includes: a polishing portion that polishes a target object while being rotated; and a polishing control portion that controls a rotation speed of the polishing portion by measuring a change in a frictional force of the polishing portion, and forming the exposed portion of the upper surface of the second main insulation layer by polishing the second auxiliary insulation layer includes: measuring the change in the frictional force of the polishing portion by sensing the rotation speed of the polishing portion by the polishing control portion; and stopping rotation of the polishing portion at the time that the frictional force is changed by the polishing control portion.
 9. A display device, comprising: a substrate; a first gate metal wire that is disposed on the substrate; a first insulation layer that covers the first gate metal wire; a second gate metal wire that is disposed on the first insulation layer; a second main insulation layer that covers the second gate metal wire; a second auxiliary insulation layer that is disposed on the second main insulation layer; and a first data metal wire that is disposed on the second main insulation layer and the second auxiliary insulation layer, wherein: an upper surface of the second auxiliary insulation layer is disposed on the same horizontal plane as a part of an upper surface of the second main insulation layer, the uppermost layer of the second main insulation layer includes a silicon nitride, and the second auxiliary insulation layer includes a silicon oxide.
 10. The display device as claimed in claim 9, further comprising: a third main insulation layer that covers the first data metal wire; a third auxiliary insulation layer that is disposed on the third main insulation layer; and a second data metal wire that is disposed on the third main insulation layer and the third auxiliary insulation layer, wherein: an upper surface of the third auxiliary insulation layer is disposed on the same horizontal plane as a part of an upper surface of the third main insulation layer, and the third main insulation layer includes a silicon nitride.
 11. The display device as claimed in claim 10, wherein a part of the upper surface of the third main insulation layer that is disposed between the first data metal wire and the second data metal wire directly contacts the second metal wire.
 12. The display device as claimed in claim 11, wherein a thickness of the third main insulation layer is smaller than a thickness of the second main insulation layer. 